Cell wall disruption, membrane damage, and decrease in the expression of Yrp1 virulence factor in Yersinia ruckeri by...

Area of Science:

• Aquatic microbiology
• Natural product chemistry
• Bacterial pathogenesis

Background:

• Antibiotic resistance necessitates alternative treatments for bacterial diseases.
• Propolis, a natural resin, exhibits promising antimicrobial properties.
• Yersinia ruckeri is a significant pathogen affecting aquaculture.

Purpose of the Study:

• To evaluate the efficacy of propolis ethanol extract (PEE) against Yersinia ruckeri.
• To investigate PEE's impact on bacterial cell structure and gene expression.
• To explore PEE as a potential alternative to conventional antibiotics in aquaculture.

Main Methods:

• Scanning electron microscopy (SEM) to assess cell wall and membrane integrity.
• Measurement of NAD+/NADH ratio and reactive oxygen species (ROS) production.
• Quantification of virulence factor (yrp1) gene expression.

Main Results:

• PEE induced significant damage to the bacterial cell wall and cytoplasmic membrane.
• A decrease in the NAD+/NADH ratio and increased ROS production were observed.
• PEE significantly reduced the expression of the Y. ruckeri virulence factor, yrp1.

Conclusions:

• Propolis ethanol extract possesses multiple antibacterial mechanisms against Y. ruckeri.
• PEE acts through both structural damage and functional disruption of bacterial cells.
• Propolis demonstrates potential as a viable alternative to antibiotics for treating Y. ruckeri infections.